Internal linking

Internal linking is the set of links from one page of a website to another page of the same site. It is how a crawler discovers pages, how it learns what a page is about from the words around the link, and how a reader gets from where they landed to what they came for.

What counts as a link

Google follows a link reliably only when it is an <a> element with an href that resolves to a URL. Navigation built from click handlers, script-scheme addresses or elements that only look like links may be parsed and may not. The same guidance asks for anchor text that is descriptive, short and relevant to both ends of the link, never empty and never a bare click here, and states the one structural rule: every page you care about should be linked from at least one other page on the site.

Why it decides what a crawler knows

This site’s audit of 9,483 small-business sites fetched each homepage and then the contact and about pages where the homepage linked to them. A contact page the homepage did not link was, for the crawler, not there. Of the sites audited, 34.1% had no postal address a machine could parse on any fetched page, and the crawler cannot tell whether the address existed on an unlinked page or nowhere. An assistant fetching a site on a buyer’s behalf has the same view: it starts where it lands and follows the links it finds. The full results are in what 9,483 small business websites serve to an AI crawler.

A question that comes up

Do internal links need rel="nofollow"?

No. Google’s guidance reserves nofollow for links to sources you do not trust, sponsored for paid placements and ugc for content visitors wrote, and says not to put nofollow on every outbound link either. A link from one of your own pages to another carries none of these. Adding one tells the crawler to discount a path through your own site.

Sources

Google Search Central, SEO link best practices. The audit figure is this site’s own; sample drawn per metro and trade, percentages describe the sample.